Two positive charges of magnitude $q$ are placed at the ends of a side $1$ of a square of side $2a$. Two negative charges of the same magnitude are kept at the other corners. Starting from rest, if a charge $Q$, moves from the middle of side $1$ to the centre of square, its kinetic energy at the centre of square is
$\frac{1}{{4\pi \,\,{\varepsilon_{0}}}}\,\frac{{2qQ}}{a}\,\left( {1\,\, - \,\frac{1}{{\sqrt 5 }}} \right)$
$zero$
$\frac{1}{{4\pi \,\,{\varepsilon_{0}}}}\,\frac{{2qQ}}{a}\,\,\left( {1\,\, + \,\,\frac{1}{{\sqrt 5 }}} \right)$
$\frac{1}{{4\pi \,\,{ \varepsilon_{0}}}}\,\frac{{2qQ}}{a}\,\left( {1\,\, - \,\frac{2}{{\sqrt 5 }}} \right)$
For an infinite line of charge having charge density $\lambda $ lying along $x-$ axis, the work required in moving charge $q$ from $C$ to $A$ along arc $CA$ is :-
A point chargr $Q$ is fixed A small charge $q$ and mass $m$ is given a velocity $v_0$ from infinity & perpendicular distance $r_0$ as shown. If distance of closest approach is $r_0/2$. The value of $q$ is [Given $mv_0^2 = \frac{{{Q^2}}}{{4\pi { \in _0}\,{r_0}}}$]
An alpha particle is accelerated through a potential difference of ${10^6}\,volt$. Its kinetic energy will be......$MeV$
A metal ball of radius $R$ is placed concentrically inside a hollow metal sphere of inner radius $2R $ and outer radius $3R$. The ball is given a charge $+2Q$ and the hollow sphere a total charge $- Q$. The electrostatic potential energy of this system is :
The work done to take an electron from rest where potential is $-60\, V$ to another point where potential is $-20\, V$ is given by.....$eV$